Abstract : The potential of energy savings in the EU has been evaluated in the recent years. On a technical basis, it is frequently said that the amount of energy services delivered could increase by a factor two while using 50 % less energy. The EU green paper for energy efficiency published in June 2005 and the resulting European Action Plan for Energy Efficiency indicate that the economic energy saving potential is higher than 20 % of the total energy consumption in the EU. On the same time, markets face barriers to fill the gap between this economic energy savings potential and the actual observed energy consumption. An investigation of the evaluation methods for assessing the energy savings potential at a global level introduces many assumptions. The paper reports the different issues to be addressed in order to evaluate the energy savings potential at a regional or national level. Results obtained at EDF/R&D on technical potentials of individual energy end uses in France are given. The aggregation and the accessibility of these potentials are discussed but not quantified, while it is considered at the present time that the uncertainty is still too high to enable a consistent quantification.